Interpretive Summary: Aflatoxins are cancer-causing chemicals produced by a mold called Aspergillus flavus. This study was to determine which part of rice the Aflatoxins were concentrated in. It was found that the majority of the toxin was found in brown rice and white rice only contained about ¼ as much Aflatoxins. This means that contaminated rice should be used as white rice to diminish the chances of toxicity. This information is very important for food and feed producers.

Technical Abstract:
The objective of this study was to determine the distribution of an economically-important class of mycotoxins, the aflatoxins, in rice milling fractions. Rice plants grown under field production condition are frequently infected with types of pathogenic fungi which produce toxic metabolites (mycotoxins). Paddy (seeds) rice from healthy plants in the field were collected and stored on a farm under humid, poorly-ventilated conditions. Samples were milled into four fractions (hulls, brown rice, bran, and white rice), and analyzed for aflatoxins (aflatoxins B1, B2, G1, and G2) using a validated method. Rice fractions from healthy plants, which contained low levels of aflatoxins (<1 ng/g), were used to determine the efficiency of the extraction method. Seeds stored under poor conditions were found to be contaminated with aflatoxins B1 and B2 as were the fractions. The sum of AFB1 and AFB2 in paddy rice, hulls, brown rice, bran and while rice were 141, 39, 158, 367, and 56 µg kg-1, respectively. The ratio of aflatoxin B1 and B2 was about 10:1. AFG1 and AFG2 were less than 1 µg kg-1. Thus, brown rice contained 92.9% of the aflatoxins in paddy rice, whereas white rice contained only 27.9%.